Remove Directories in Windows OS

I have installed an Eclipse based tool, that has created multiple folders with in a single folder,
Eg:
C:\projects\cas\build\d1\d1\d1\d1\d1\d1\d1\d1\d1\d 1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\d1\ d1\d1\d1\d1\d1\d1....
and so on.

I wanted to delete the files. But i could not.
I tried using the following in cygwin.
$rm -r d1/ from the build directory.